Testing.38 Special vs 9mm 

Not so long ago, when you talked about self-defense firearms, especially for law enforcement officers, you were talking about some sort of revolver. More often than not, those revolvers were chambered in .38 Special. Times change, however, and now 9mm is the cartridge of choice for defensive handguns. These two cartridges have dominated the American handgun market for almost a century, so a comparison of .38 Special vs 9mm is probably in order. 

One of the interesting things about .38 Special vs 9mm is that they both hit the shooting world within ten years of each other. .38 Special was a response to the experience of the U.S. Army using revolvers slightly the shorter .38 Long Colt cartridge in the Spanish-American war. The ineffectiveness of that round versus the Mora tribe in the Philippines drove the Army to seek a replacement sidearm. If you’re thinking “Hey, isn’t that why the Army went with the .45ACP round and the 1911?,” you’re right, it was. However, the revolver was still a big part of the firearms world back then, and the Navy (and others) still needed their wheelguns. 

The Origins Of .38 Special and 9mm

In 1899, Smith and Wesson rolled out the .38 Special cartridge with their Military & Police revolver. Two years after that, Georg Luger took his 7.65x21mm cartridge and turned it into the 9x19mm cartridge we know and love today. With the introduction of the “wonder nine,” 9mm really took off, and it replaced the .38 Special round as the caliber of choice for law enforcement agencies. 

Recently, though, there’s been a renewed interest in revolvers, especially when used as a pocket pistol or in deep concealment situations. There are advantages to using a wheelgun for pocket carry. The lumpy shape of a revolver means your pistol won’t scream “gun”  as it rests inside a holster in your pocket. The operation of a revolver isn’t affected if it makes contact with your clothing or the bad guy when fired, a useful feature in a pocket gun. Lastly, the lower round count of a revolver isn’t that big of a deal in a gun that’s meant to be used as a backup or in extreme situations. 

All of these factors have sparked a renewed interest in .38 Special and the advantages of .38 Special vs. 9mm. Let’s begin by looking at some of the upfront differences between .38 Special vs 9mm.

9mm Is Less Expensive

9mm is undoubtedly the least-expensive centerfire cartridge out there. This means, dollar for dollar, you’ll send fewer rounds downrange with .38 Special vs 9mm, which can affect your practice regimen and training time. 

Both Are Available Almost Everywhere

Granted, it’s a bit harder to find 9mm ammo since the Walmart ammo ban of 2019, but you get the idea. Every self-respecting gun shop is going to have some sort of 9mm ammo on their shelves, and there’s a wide variety of bullet sizes, weights and types for sale on our site as I type this. .38 Special is very popular as well. However, the sheer demand for 9mm ammo means that you’ll see fewer varieties of .38 Special vs 9mm either online or in-person.

Both Are Used In Revolvers 

Fun fact: 9mm is a popular choice in the revolver-specific divisions of practical shooting sports such as USPSA and IDPA. Both sports have minimums placed on handgun power, and a typical 115 grain 9mm FMJ is powerful enough to qualify. This is not true of .38 Special, as the standard 130 or 135 grain FMJ round falls a bit short, leading a competitor to shoot +P ammo, trade in their .38 revolver for something in .357 Magnum or shoot a 9mm revolver and reload using moon clips.   

Both Are Used In Rifles

Okay technically, these might be considered carbines and not rifles, but we’ll leave that hair to be split some other day. AR-pattern guns chambered in 9mm are the de facto standard in the  Pistol Caliber Carbine (PCC) division of USPSA, and lever-action rifles chambered in .38 Special are very common in the sport of Cowboy Action Shooting. 

They’re Both Terrific Defensive Cartridges

.38 Special stopped many a felon in its day, and 9mm is the current defensive round of choice for armed citizens, law enforcement and the military. But is 9mm that much better? To find out the effectiveness of .38 Special vs 9mm as a defensive round, we’ll shoot five rounds each from four different guns into blocks of clear ballistics gel. 

The ammo we’ll use in this test is Speer Gold Dots, a very common defensive round for both calibers. We’ll use the 130 grain version in .38 Special, and the 147 grain version in our 9mm guns. These days, .38 Special is a common round for snub-nosed revolvers as well as guns with longer barrels. To test this, we’ll use a Ruger LCR with a 1.87 inch barrel, and our comparison gun will be a Sccy CPX-2 with a 3.1 inch barrel. We’ll also shoot the same ammo from a S&W M+P with a 4 inch barrel and a Glock 19 with a 4.02 inch barrel as our test service-sized pistols. 

Test results

	Barrel Length	Avg Vel (FPS)	Muzzle Energy (ft/lbs)	Avg Penetration (in)	Bullet Width (inches)
.38 Special Ruger LCR	1.87	854	202	13.8	0.46
.38 Special S&W M+P	4	909	229	13.5	.047
9mm Sccy CPX-3	3.1	902	266	14.5	0.58
9mm Glock 19	4.02	992	321	16.9	0.56

Two of the biggest differences between the .38 Special vs 9mm defensive ammo we tested was the expansion of the round in the testing medium and the penetration of the round in the target. To be clear, all of the rounds we tested met or exceeded the FBI standard for penetration into gel. This means all of them are very suitable for use as a defensive pistol. The 9mm may have penetrated further, but all the rounds met the 12 inches minimum needed to pass the FBI standard. 

However, the expansion of the bullet differed with 38 Special vs. 9mm. The 147 grain 9mm rounds, on average, opened up 0.1 inches more than the 130 grain .38 Special rounds. The larger expansion means there’s more opportunity for each bullet to cause tissue damage as it makes its way through the body towards the vital areas that can stop a threat. This extra damage is useful, but real-world experience has shown that hits which penetrate into the ocular or thoracic cavities are the ones that stop the threat. The bottom line is, bullet expansion is nice, but expansion that doesn’t have sufficient penetration won’t be enough to stop a threat to your life. This could have been a problem with the lower-powered .38 Special cartridge, but all the rounds in our test passed the penetration test, at the expense of their overall expansion

The Final Word on 38 Special vs 9mm

Ultimately both 9mm and .38 Special are reliable rounds with over a century each of proven results. Therefore, the choice of .38 Special vs 9mm becomes more about the guns they are used in than the cartridges themselves. If you’re more comfortable running a semi-auto, 9mm should be your choice. If you prefer the simplicity of a revolver and are willing to put up with fewer rounds, carry a .38 Special, and carry it with confidence. Either way, the 1-2 punch of a modern, reliable firearm and the consistent performance of modern ammunition means you’ll have a gun and ammo combination that will be ready for you when you need it the most.